We investigate the physics reach and potential for the study of B-meson decays to invisible final states at the Future Circular Collider running electron-positron collisions at the Z pole (FCC-ee). Signal and background candidates are simulated for a proposed multipurpose detector, including inclusive contributions from Z decays to leptons or quarks. Signal candidates are selected by a mixture of rectangular cuts and a multiclass boosted decision tree classifier. We determine that branching fractions above 7.6×10−9 (9.7×10−9) would be excluded at 90% (95%) confidence level, and branching fractions above 3.0×10−8 would be within discovery reach at FCC-ee if 6×1012Z bosons are produced.
@article{arxiv.2508.04471,
title = {Prospects of searches for invisible $B$-meson decays at FCC-ee},
author = {P. Alvarez Cartelle and M. Kenzie and R. Mangrulkar and A. R. Wiederhold and E. Wood},
journal= {arXiv preprint arXiv:2508.04471},
year = {2026}
}